Miller (elbow) shifted his rehab assignment Thursday to Triple-A Las Vegas.
Miller is moving along in the Athletics' minor-league system as he completes his recovery from the mild UCL sprain that sent him to the injured list back in May. He allowed two earned runs while striking out four batters across 3.2 innings (two starts) with Single-A Stockton, topping out at 32 pitches Sunday. The 25-year-old has some more work to do on the farm if he's going to return to Oakland in a full-on starting role, but early September seems like a reasonable target.